In the reaction Zn + CuSO4 → ZnSO4 + Cu, what is being replaced?
AZinc is replaced by copper
BCopper is replaced by zinc
CSulfur is replaced by zinc
DOxygen is replaced by copper
Zinc (more reactive) replaces copper (less reactive) in the copper sulfate compound. Copper is pushed out and appears as free copper metal, while zinc takes copper's place in the compound, forming zinc sulfate.
Question 2 True / False
A single replacement reaction will generally occur when you mix an element with a compound.
TTrue
FFalse
Answer: False
A single replacement reaction only occurs if the free element is more reactive than the element it would replace. For example, copper cannot replace zinc in zinc sulfate because copper is less reactive than zinc. An activity series helps predict whether a given replacement will occur.
Question 3 Short Answer
What determines whether a single replacement reaction will occur between a metal and a compound containing a different metal?
Think about your answer, then reveal below.
Model answer: The relative reactivity of the two metals — the free metal must be more reactive than the metal in the compound.
Elements have an inherent tendency to react, called reactivity. An activity series ranks metals from most to least reactive. A metal higher on the series can replace a metal lower on the series from a compound, but not the other way around. This is why zinc can replace copper but copper cannot replace zinc.